1. Field of the Invention
The present invention relates to a pancake-type bifilar winding module using a superconducting wire and a winding bobbin therefor. More particularly, the present invention relates to a pancake-type bifilar winding module for use in manufacturing a superconducting fault current limiter, and a winding bobbin capable of enabling bifilar winding of a superconducting wire by accommodating the characteristic of the superconducting wire, such as the curvature of the superconducting wire.
2. Description of the Related Art
A superconductor is a synthetic material that has superconductivity under predetermined conditions. In particular, the superconductor has very low or no electrical resistance under predetermined conditions of temperature, intensity of magnetic field, and current density, but it exhibits high resistance when conditions such as quench phenomena, superconductivity phase transition, and normal conductivity phase transition are changed.
Due to these characteristics, if superconducting elements are inserted into a power system in series, no electrical loss occurs since the resistance of the superconductor is zero during normal operation of the power system. However, the superconductor has high resistance when the power system fails since the fault current exceeds the critical current of the superconductor. Due to the increased resistance of the superconductor, the fault current is limited. Accordingly, this system is called a superconducting fault current limiter.
A superconducting fault current limiter is a piece of power machinery used to prevent power interruption by effectively limiting over-current generated by a short-circuit or the disconnection of a circuit, and is considered as the only substitute which can overcome the limitations of a circuit breaker which has been used in current power systems so far.
This superconducting fault current limiter has been manufactured using various kinds of superconductors. Prevalent superconductors are a thin film, a thick film, and a bulk device.
However, these superconductors have the following disadvantages. First, it is difficult to modify their size and shape. Second, the fault current limiter must be structured to have minimal inductance, but they are difficult to construct to have a small inductance. Third, there are limitations in manufacturing of the thin film, the thick film, and the bulk device compared to a wire. Furthermore, it is difficult to purchase them, and they are expensive.